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1.
Eur Phys J C Part Fields ; 82(2): 121, 2022.
Article in English | MEDLINE | ID: mdl-35210938

ABSTRACT

We present the novel implementation of a non-differentiable metric approximation and a corresponding loss-scheduling aimed at the search for new particles of unknown mass in high energy physics experiments. We call the loss-scheduling, based on the minimisation of a figure-of-merit related function typical of particle physics, a Punzi-loss function, and the neural network that utilises this loss function a Punzi-net. We show that the Punzi-net outperforms standard multivariate analysis techniques and generalises well to mass hypotheses for which it was not trained. This is achieved by training a single classifier that provides a coherent and optimal classification of all signal hypotheses over the whole search space. Our result constitutes a complementary approach to fully differentiable analyses in particle physics. We implemented this work using PyTorch and provide users full access to a public repository containing all the codes and a training example.

2.
Phys Rev Lett ; 124(16): 161803, 2020 Apr 24.
Article in English | MEDLINE | ID: mdl-32383937

ABSTRACT

The experimental results on the ratios of branching fractions R(D)=B(B[over ¯]→Dτ^{-}ν[over ¯]_{τ})/B(B[over ¯]→Dℓ^{-}ν[over ¯]_{ℓ}) and R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ denotes an electron or a muon, show a long-standing discrepancy with the standard model predictions, and might hint at a violation of lepton flavor universality. We report a new simultaneous measurement of R(D) and R(D^{*}), based on a data sample containing 772×10^{6} BB[over ¯] events recorded at the ϒ(4S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. In this analysis the tag-side B meson is reconstructed in a semileptonic decay mode and the signal-side τ is reconstructed in a purely leptonic decay. The measured values are R(D)=0.307±0.037±0.016 and R(D^{*})=0.283±0.018±0.014, where the first uncertainties are statistical and the second are systematic. These results are in agreement with the standard model predictions within 0.2, 1.1, and 0.8 standard deviations for R(D), R(D^{*}), and their combination, respectively. This work constitutes the most precise measurements of R(D) and R(D^{*}) performed to date as well as the first result for R(D) based on a semileptonic tagging method.

3.
Phys Rev Lett ; 114(15): 151601, 2015 Apr 17.
Article in English | MEDLINE | ID: mdl-25933306

ABSTRACT

We report the measurement of the direct CP asymmetry in the radiative B¯â†’X(s+dγ) decay using a data sample of (772 ± 11)×10(6) BB[over ¯] pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The CP asymmetry is measured as a function of the photon energy threshold. For Eγ*≥2.1 GeV, where Eγ* is the photon energy in the center-of-mass frame, we obtain A(CP)(B¯â†’X(s+dγ))=(2.2±3.9±0.9)%, consistent with the standard model prediction.

4.
Nutr. hosp ; 26(6): 1345-1349, nov.-dic. 2011. tab, ilus
Article in Spanish | IBECS | ID: ibc-104809

ABSTRACT

Introducción: La desnutrición infantil conlleva una elevada morbimortalidad a nivel mundial. Los centros de recuperación nutricional son fundamentales en el tratamiento de los niños desnutridos. Objetivo: Evaluar la efectividad de la intervención terapéutica realizada en menores de 5 años con desnutrición aguda en un Centro de Recuperación Nutricional. Métodos: Se realizó un estudio retrospectivo descriptivo mediante revisión de historias clínicas de menores de 5 años ingresados en el Centro de Recuperación Nutricional Infantil de Matagalpa, Nicaragua, entre Enero de 2006 y Julio de 2010. Resultados: La mediana de edad al ingreso fue de 17,2 meses (p25:10,7-p75:27,2), y la de estancia en el centro de 92 días (p25:61,5-p75:134,5). El grado de desnutrición aguda al ingreso fue: grave en el 45% de niños, moderado en el 24% y con riesgo de desnutrición en el 31%. El 86% de los niños al alta presentaba una nutrición correcta. La mediana de porcentaje de ganancia ponderal en el primer mes de estancia fue del 15% (p25:12,6-p75:17,4). La mediana de gramos ganados/kg/día fue de 3,7 (p25:2,6-p75:5,4), siendo mayor en menores de 6 meses (4,6 g/kg/día; p25:4,3-p75: 7,5). La tasa de niños curados fue del 87,5%, la tasa de fallecidos 0% y la tasa de abandonos 9%. Discusión: El centro evaluado funciona correctamente, y supera los indicadores de calidad recomendados internacionalmente. Sin embargo, quedan lejos las recomendaciones de una estancia promedio de 1-2 meses y de una ganancia ponderal promedio de 8 g/kg/día. Por tanto, el Centro de Recuperación Nutricional realiza una intervención efectiva, pero no eficiente (AU)


Introduction: Child malnutrition carries a high morbimortality worldwide. Therapeutic feeding centers are essential in the treatment of malnourished children. 
Objective: To evaluate the effectiveness of the therapeutic intervention in under-5 undernourished children in a Therapeutic Feeding Center. Methods: A retrospective descriptive research was made through the revision of the clinical histories of children under 5 years that entered the Nutritional Recovery Center for Children in Matagalpa, Nicaragua, from January 2006 to July 2010. Results: Median age at admission was 17.2 months (p25:10.7-p75:27.2) and median stay in the center was 92 days (p25:61.5-p75:134.5). Prevalence of patients with severe acute malnutrition was 45%, moderate acute malnutrition 24% and risk for malnutrition 31%. At discharge 86% of patients were properly nourished. Median weight gain percentage after the first month in the center was 15% (p25:12.6-p75:17.4). Median weight gain was 3.7 g/kg/day (p25:2.6-p75:5.4), being higher in children under 6 months (4.6 g/kg/day; p25:4.3-p75:7.5). Cured rate in the center was 87.5%, being the death rate 0% and the abandonment rate 9%. Discussion: The center evaluated works adequately, and fulfills the internationally recommended quality indicators. However, recommended average stay of 1-2 months and average weight gain of 8 g/kg/day are far of being fulfilled. Therefore, the Nutritional Recovery Center performs an effective intervention, but it's not efficient enough (AU)


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child Nutrition Disorders/epidemiology , Infant Nutrition Disorders/epidemiology , Nutrition Rehabilitation , Nicaragua/epidemiology , Evaluation of Results of Therapeutic Interventions , Applied Nutrition Programs/organization & administration , Nutritional Support/methods
5.
Nutr Hosp ; 26(6): 1345-9, 2011.
Article in Spanish | MEDLINE | ID: mdl-22411381

ABSTRACT

INTRODUCTION: Child malnutrition carries a high morbimortality worldwide. Therapeutic feeding centers are essential in the treatment of malnourished children. OBJECTIVE: To evaluate the effectiveness of the therapeutic intervention in under-5 undernourished children in a Therapeutic Feeding Center. METHODS: A retrospective descriptive research was made through the revision of the clinical histories of children under 5 years that entered the Nutritional Recovery Center for Children in Matagalpa, Nicaragua, from January 2006 to July 2010. RESULTS: Median age at admission was 17.2 months (p25:10.7-p75:27.2) and median stay in the center was 92 days (p25:61.5-p75:134.5). Prevalence of patients with severe acute malnutrition was 45%, moderate acute malnutrition 24% and risk for malnutrition 31%. At discharge 86% of patients were properly nourished. Median weight gain percentage after the first month in the center was 15% (p25:12.6-p75:17.4). Median weight gain was 3.7 g/kg/day (p25:2.6-p75:5.4), being higher in children under 6 months (4.6 g/kg/day; p25:4.3-p75:7.5). Cured rate in the center was 87.5%, being the death rate 0% and the abandonment rate 9%. DISCUSSION: The center evaluated works adequately, and fulfills the internationally recommended quality indicators. However, recommended average stay of 1-2 months and average weight gain of 8 g/kg/day are far of being fulfilled. Therefore, the Nutritional Recovery Center performs an effective intervention, but it's not efficient enough.


Subject(s)
Child Nutrition Disorders/therapy , Child Nutrition Disorders/complications , Child Nutrition Disorders/epidemiology , Child, Preschool , Edema/epidemiology , Edema/etiology , Female , Humans , Infant , Length of Stay , Male , Nicaragua/epidemiology , Protein-Energy Malnutrition , Retrospective Studies , Treatment Outcome , Weight Gain/physiology
6.
Phys Rev Lett ; 104(2): 021801, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20366585

ABSTRACT

We present the partial branching fraction for inclusive charmless semileptonic B decays and the corresponding value of the Cabibbo-Kobayashi-Maskawa matrix element |V{ub}|, using a multivariate analysis method to access approximately 90% of the B-->X{u}lnu phase space. This approach dramatically reduces the theoretical uncertainties from the b-quark mass and nonperturbative QCD compared to all previous inclusive measurements. The results are based on a sample of 657x10{6} BB[over ] pairs collected with the Belle detector. We find that DeltaB(B-->X{u}lnu;p(l){*B}>1.0 GeV/c)=1.963x(1+/-0.088{stat}+/-0.081{syst})x10{-3}. Corresponding values of |V{ub}| are extracted using several theoretical calculations.

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